Bag machine



y 1938- w. H. ENGEL 2,116,566

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y w. H. ENGEL 2,116,566

BAG MACHINE Original Filed May 18, 1933 2 Sheets-Sheet 2 Patented May l0, 1938 UNITED STATES BAG MACHINE William H. Engel, Mount Vernon, Ohio, assignor to Shellmar Products Company, Chicago, 111., a corporation of Delaware mamas May 1a, 1933, Serial No. 671,672

Renewed September 28, 1936 4 Claims. (CI. 93-19) The present invention relates to bag machines and has particular reference to improvements in bag machines of the type described in my copending application, Serial No. 638,758, filed October 20, 1932, which application discloses a bag machine particularly adapted for the production of bags from transparent cellulose sheeting and similar materials.

In the production of bags it is essential from an economical standpoint that the bag making machine be adapted for the production of bags of varying lengths and widths. In other words, the machine should have a somewhat comprehensive range of sizes in order that the needs of. various customers may be filled without necessitating a separate machine for each size. As described in the aforesaid application, the width of bags may be regulated by changing the width of the former plates about which a sheet of the bag making material is formed into a tube from which bag lengths are subsequently severed. However, for the production of bags of different lengths it was necessary to employ cutting rolls having circumferences corresponding to the length of the bag to be produced. For this, reason several cuttings units were required for each machine( A principal object of the present invention is the provision of a bag making machine from which bags of different lengths may be produced without changing the cutting units of the machine.

An additional object is to provide a bag making machine having an improved driving mechanism for severing bag lengths from a tube.

These and other objects will be' evident from a v consideration of the following description and by reference to the accompanying drawings, in which Fig. 1 is a diagrammatic view of the operating units of the bag machine to which my invention relates;

Fig. 2 is a side view of the machine showing the driving mechanism therefor;

Fig. 3 is a view of the cutting unit of the machine;

Fig. 4 is a side view of the mechanism shown in Fig. 3;

Fig. 5 is a diagrammatic view showing the manner in which a web of bag forming material is formed into a tube from which bag lengths are severed; and

Fig. 6 is a perspective view of the tube-forming mechanism. i

As shown in the drawings, a web ill of transparent cellulose sheeting or other bag forming material is unwound from a roll, I! and passed about a series of tension controlling rollers l2 and then downwardly at an angle beneath a forming shoe N. The web is straightened into a horizontal path of travel beneath the shoe, whereby the outer edges of the web are turned upwardly in a manner well known in the art. The outer edges are then turned over in overlapped relation and glued together to complete the formation of a tube, as shown in Fig.5. An upper feed roll I! and a lower feed roll I! progress the tube beneath an upper cutting roll l6 and a lower cutting roll I! which are provided with peripheral knives l8 and I9, respectively, these knives making a kiss or surface contact with a flat cutting shoe 20 which reciprocates between the two cutting rolls.

The cutting rolls l6 and I! act to cut the horizontal portions of the tube, leaving a bag length attached to the tube by means of the vertical portions of the bag forming material in the tube. This partially severed bag length passes'between an upper feed roll 2| and a lower feed roll 22 and then through an upper transfer roll 23 and a lower transfer roll 24 which are traveling at a higher peripheral speed than the speed of the tube, thereby acting to jerk the bag length and tear it away from the. tube. From the transfer rolls the bag may be passed through a conventional bottom forming mechanism to complete the formation of the bag.

A table portion 25 is mounted beneath the former plate I3 and an arch 26 is mounted above the former plate. An arm 21 is pivotally mounted to a shaft 28 which is supported by the arch 26 for reciprocation longitudinally of the plate l3. The former I3 is secured to an upwardly extending shaft 29 supported by a second arch 30. The end of arm 21 is pivotally attached at 3i to reciprocating shoe 20, the latter being mounted in a slot in the former l3. Adjacent the side of the machine a second arm 32 is keyed to shaft 28 of the arm 21 and extends downwardly substantially the same distance. To the lower portion of this arm 32 is secured a longitudinally extending rod 33. The connection of arm 32 and rod 33 is made by means of a forward spring 34 and a rear spring 35 maintained in position bysuitable nuts screwed on the rod 33. It will be seen that movement of the rod 33 in either direction will cause corresponding movement of the arm 32 and as a consequence movement of the cutting shoe 2!], the motion in both directions being cushioned by springs 34 and 35. g

To an extension of shaft 36 upon which the cutting roll it is mounted is keyed a crank disk 31 having a diametric T-slot 33. The slot is so positioned as to point in the same direction as a radius of the cutting roll l6 drawn to the center of the cutting knives. Within the T-slot 38 is mounted a cam nut 39 having a locking sleeve 40 pivotally attached thereto. The locking sleeve 40 is rigidly connected to the end of rod 33. Upon rotation of the cutting roll I 3 from top position into operative position with the cutting knives facing downwardly the rod 33 is first pushed toward the feed.

end of the machine, thereby causing the cutting shoe 2!! to be retracted from its forward position between the cutting rolls. After the cutting roll reaches the position shown in Fig. 3 the rod 33 is pulled toward the delivery end of the machine, thereby causing the cutting shoe 2!! to move forwardly between the cutting rolls. Thereafter the rod 33 is pulled toward they feed end of the machine, the cycle being completed when the cutting knives are rotated beyond the position shown in Fig. 3. It will be seen that the cutting shoe moves in a cycle in which it is moved from its furthest position toward the feed end of the machine until the moment of operation of the cutting knives and thereafter moves to a stop position when the cuttingrolls have rotated 180 beyond the position shown in Fig. 3. For a further 180 of rotation of the cutting rolls the cutting shoe is retracted from its furthest position toward the delivery end of the machine to its position toward the feed end of the machine.

Cutting rolls l3 and II are similar in construction, but-are provided with differently shaped knives in order that the lips of the bag may be in offset relation. Plates 4| are secured to cutaway portions of rolls i6 and I! by means of screws 42, and these plates have protruding resilient faces 43 secured thereto. These resilient face members 43, which preferably are composed of rubber, extend sufficiently far beyond the surface of the cutting rolls to engage the cutting shoe 20. The material of the tube is pressed between the rubber members 43 and the cutting shoe with sufficient pressure to insure that the rubber members 43, the tube, and the cutting shoe 20 will travel together during the cutting operation, the resiliency of springs 34 and 35 allowing the motion of the cutting shoe to correspond with the motion of the cutting roll regardless of slightly different driving speeds imparted to the cutting shoe by rod 33.

As the cutting rolls rotate into operative position the cutting shoe is gripped, through the bag material, by the rubber members 43. Pressure of these members against the cutting shoe causes the rubber to be compressed sufliciently to permit knives 44, mounted between adjacent rubber members 43, to make a surface or kiss contact with the cutting shoe, thereby cutting the bag material on each horizontal side of the cuttin shoe.

The resulting bag length remains attached to the tube by means of the material along the vertical edges of the cutting shoe. From the cutting rolls, the partially severed bag lengths pass between idler rolls 2| and 22 and then between transfer rolls 23 and 24, the latter rolls having a higher peripheral speed and acting to tear the partially severed bag lengths from the tube.

To drive the machine, a belt 45 rotates shaft 46 upon which is secured a gear 41. The latter gear drives gear 48 which is carried on an intermediate portion of shaft 49. An intermediate or idler gear 50 is driven by gear 48, and the former gear drives gear 5| mounted on shaft 52 of the lower transfer roll 24. Upper transfer roll 23 is driven by gear 53 on shaft 54 meshing with gear II.

A change gear 55, mounted on one end of shaft 49, drives on one side a large idler gear 56 which is mounted on a swing arm 51, the latter being pivoted about shaft 53 of the lower feed roll 22. The idler gear meshes with a gear 59 on shaft 58, thereby providing driving means for roll 22, and gear 59 drives a similar gear 60 mounted on shaft CI of upper feed roll 2|.

0n the opposite side of changegear 55 and meshing therewith is an idler gear 62 which is mounted on a swing arm 63, the latter being pivoted about shaft 64 of the lower drive roll l5. Gear 62 meshes with a gear 65 keyed to shaft 64, and gear 65 drives a similar gear 86 which is keyed to shaft 61 of the upper drive roll l4.

On the opposite end of shaft 49 from change gear 55 is mounted an elliptical gear 63 which is adjustable in its position on the shaft. This elliptical gear meshes with a complementary elliptical gear 69 carried by an idler shaft I0. Shaft 10 has a gear H on its opposite end and the latter drives a similar gear 12 on shaft 13 of the lower cutting roll II. The upper cutting roll is driven by the meshing of a gear 14 on shaft 13 with a similar gear 15 on shaft 36 of the upper cutting roll.

It will be observed that change gear-55 and elliptical gear 63 are on the same shaft, and as a result of this construction the cutting rolls are rotated in one to one rotation with the change gear, regardless of the size of the latter. By empldyingdifierent size change gears, the speed of the tube through the machine may be adjusted to different velocities without affecting the speed of the cutting rolls. More particularly, where a larger change gear is employed, the mechanism for progressing the tube of bag-forming material is increased in speed whereby more tube length passes between the cutting rolls for each rotation of the latter than in the case of a smaller change gear. Consequently, a longer bag length is severed by the cutting rolls. Where a shorter bag length is desired, a smaller change gear is employed whereby the speed of the mechanism for progressing the tube through the machine is slcilwed up with respect to the speed of the cutting ro s.

Where regular gears are employed instead of elliptical gears-68 and 69 the revolution of the cutting rolls through 360 is at a constant speed. For this reason it is necessary to employ different sized cutting rolls for each size bag which it is desired to produce, since the peripheral speed of the cutting rolls must be substantially the same as the speed of the tube at the moment of the cutting operation. By employing elliptical gears it is possible to use a single set of cutting rolls for a relatively -wide range of bag lengths.

In rotation the elliptical gears, which are of complementary construction in that the teeth of one gear are offset with respect to the teeth of the other gear, impart a cyclic motion to the cutting rolls in which the latter rotate at their slowest speed when the elliptical gears are in the position shown in Fig. 4 and increase through 180 to their highest speed. Through the next 180 rotation the cutting rolls decrease in speed to their minimum. By properly adjusting the position of the elliptical gears, the cutting rolls may be given any desired speed between their minimum and maximum at the moment the cutting knives are in operative position, whereby the speedof the cutting knives may be made to cor-' respond with the speed of the tube of bag making material regardless of the size of the change gear.

The motion of the cutting rolls is never constant, due to the cyclic motion of the elliptical gears, whereas the motion of the tube is constant. In other words, the speed of the cutting rolls is constantly changing from the approximate speed of the tube which the cutting rolls may have at a point during the cutting operation. Byadjusting the position of the elliptical gears properly, it is possible to increase the speed of the cutting rolls and cutting shoe toward the moment of cutting. When this is done the rubber facing members 43 and the cutting shoe grip the tube prior to the cutting moment and at a time when the speed of the tube is greater than the speed of the cutting mechanism. The tube therefore is caused to buckle slightly, the excess material accumulating between the cutting unit and feed rolls l4 and IS. The firm contact between the rubber facing members 43 and the'cutting shoe prevents any relative movement between the cutting shoe, the bag material, and the cutting knives, thereby insuring a smooth and even out, it being understood that the cutting knives pass through the bag material and make a surface contact with the cutting shoe. After the cutting operation, the cutting rolls are increased in speed and disposition is made of the excess of bag material which accumulates as described heretofore.

For a given set of elliptical gears, bags may be produced having lengths ranging from the length obtainable at the slowest speed of the cutting rolls determined by the elliptical gears when in the position shown in Fig. 4 to the length obtainable when the elliptical gears are advanced 180. In this manner a larger number of bag sizes may be obtained without the necessity of changing the cutting rolls.

It will be seen that the structure described herein for purposes of illustration and explanation is susceptible of change without departing from the spirit of my invention, and all such modifications are intended to be included in the appended claims.

I claim:

1. In a device of the type described, means for ing a pair of intermeshing adjustable complementary elliptical gears.

2. In a device of the type described, means for forming a tube from a continuous web of ba forming material, means for progressing said tube at variable speeds, a cutting roll for'operation on said tube, a cutting shoe reciprocably mounted within said tube and traveling with said tube adjacent said cutting roll at the time the latter is in operative position, a crank disk connected to said roll, resilient means operated by said crank disk for operating said cutting shoe, and driving means for said cutting roll, including a pair of intermeshing adjustable complementary elliptical gears.

3. In a bag machine, means for forming a tube from a continuous web of bag-forming material, means i'or progressing said tube at variable speeds, a cutting roll for operation on said tube, a cutting shoe reciprocally mounted within said tube and traveling with said tube adjacent said cutting roll at the time the latter is in operative position, resilient means operated by said cutting roll for reciprocating said cutting shoe, a cutting knife on said roll, resilient material on said cutting roll on each side of said knife, and driving means for said roll, including a pair of intermeshing adjustable complementary elliptical gears.

4. In a device of the type described, means for forming a tube from a continuous web of material, means for progressing said tube at variable speeds, a cutting shoe reciprocally mounted in said tube, cutting rolls having knives operable to make a contact cut with said shoe, slack-forming rubber members on each side of said knives, and driving means for said cutting rolls, including a pair of intermeshing adjustable complementary elliptical gears.

WILLIAM H. ENGEL. 

